All Letswave pre-processing analysis scripts (.lw_script) can be opened in Letswave7 (open-source Matlab plugin, www.letswave.org).
The scripts supplied here contain example data file names and the correct datafiles need to be provided in the "load" fields.
All details of the pre-processing can be found in the EEG analysis section of the Stage 1 Registered Report (link to OSF repository: https://osf.io/9ud7x/)